Blue Bridge Cup Conventional Score

Answer: 2481215

#include<iostream>
using namespace std;
int gcd(int a,int b){
    
    
    return b==0?a:gcd(b,a%b);
}
int main(){
    
    
    int ans=0;
    for(int i=1;i<=2020;i++){
    
    
        for(int j=1;j<=2020;j++){
    
    
            if(gcd(i,j)==1)
                ans++;
        }
    }
    cout<<ans;
    return 0;
}